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Cold Front Dropping South Across the Western U.S.; Watching Threat for Tornadoes and Flooding in the South

A cold front will push south across the Western U.S. into Tuesday with mountain snow and areas of gusty to high winds. An area of low pressure will form along this front on Tuesday and bring a potential for severe thunderstorms with tornadoes and excessive rainfall in the lower to mid Mississippi River Valley. To the north, heavy snow is possible in parts of the upper Midwest. Read More >


Fast Facts:

  • Numerous severe thunderstorms tracked across northern Illinois and parts of northwest Indiana on Tuesday, September 7. 
  • Significant hail larger than golf balls fell in parts of Lee and LaSalle Counties, including near and in the towns of West Brooklyn, Compton, Paw Paw, and Earlville, with some of the hail not melting until several hours after it fell. 
  • September 7 marks the first day in 2021 during which hail at least 2" in diameter was reported in the NWS Chicago forecast area and is, so far, the day with the most hail reports in 2021. Typically, "big hail days" in our area occur during the spring months. 
  • Swaths of wind damage to mainly utility poles and trees (including some trees falling onto structures) occurred, particularly from the Lisbon and Morris areas into the Minooka, Channahon, and Manhattan areas across Kendall, Grundy, and Will Counties. An NWS storm damage survey team assessed that this damage was caused by 60-85 mph winds, with no conclusive evidence of any tornadoes.
  • There was also significant wind damage in Gibson City, IL in Ford County.
  • The potential for severe weather on Tuesday was noted already on Sunday, with increasing potential noted later Monday into Tuesday morning. A Severe Thunderstorm Watch was issued shortly after 1 PM in the afternoon with numerous Warnings issued through the event.  
  • The first NWS Chicago "Significant Severe" Thunderstorm Warning with WEA Activation was issued for baseball size hail in Earlville and northeast LaSalle County. The "Significant Severe" option for Severe Thunderstorms Warnings had been implemented in the summer of 2021. 

Recap of Severe and Flooding Reports. 

ImageMRMS Radar Reflectivity at Lowest Altitude (RALA) from 11:00 AM to 9:00 PM CDT, September 7, 2021

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Additional recaps can be found on the NWS Chicago Past Events Page
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